1. Field of the Invention
The invention relates to a latching device having a resetting device, having a triggering device, having a compression element and having supporting elements which are arranged one above the other in a housing and which, in the latched state, are acted upon with a compressive force applied via a compression element, to provide a spring-type drive.
2. PRIOR ART
Latching devices of this type for spring-type drives are employed, for example, in high-voltage circuit breakers. The storage spring contained in a spring-type drive can be kept in a stressed state by a latching device. By means of a latching device, a comparatively large amount of stored energy can be released from the stressed storage spring in a controlled manner. In order to release the stored energy, the latching device has a triggering device, which operates with an amount of energy that is small as compared with the energy to be released.
It has already been proposed to use the rolling support principle in a latching device. In this principle, four rollers are arranged above one another, the two intermediate rollers not being arranged in alignment with the two outer rollers. A compressive force is introduced from above by a supporting latch via a compression element and is transmitted to the uppermost roller, so that it is transmitted in a supporting manner to the lowest roller via the two intermediate rollers.
During the triggering process, the two intermediate rollers are displaced counter to their alignment deviation by a triggering device until the result is an alignment deviation in the opposite direction. Following a triggering process, the two intermediate rollers are at a distance from a holding position and the supporting action is canceled; the two intermediate rollers are forced out sideways and free a path for the compression element. The supporting latch bearing on the compression element is thus able to cover a predefined travel and the previously stressed storage spring is released.
However, in the case of this triggering principle, the result is that the stroke of the compression element can only be as great as the magnitude of the diameters of the two inner rollers. In the event of a desired enlargement of the stroke of the compression element, the diameters of at least the inner rollers would consequently have to be enlarged, which likewise would result in an enlargement of the overall latching device and therefore entails an increased requirement for materials and space.
Furthermore, the document DE 11 08 301 A discloses a contact arrangement for electric switches which comprises a main switching piece and a circuit-breaking switching piece comprising a plurality of individual switching pieces connected in parallel.